In motorized vehicles, the clutch enables the engine drive train to be disconnected from the axels during changes in the drive ratio. Often, the clutch provides a friction coupling between the drive train and the axels. This friction coupling (for example, contact between two fiber-compound discs) may be prone to slipping as the drive train rotations per minute (RPM) increase. To alleviate this condition, a clutch cover may be employed.
FIGS. 1 and 2 are front and back view illustrations, respectively, of a prior art clutch cover 100. The cover 100 may be employed in two and four stroke engine systems, such as Honda™ and Banshee™ motors for all terrain vehicles (ATVs). Bolts may be inserted through the holes 118 in the posts 106 to mount the cover 100 to a clutch flywheel of the engine. Heads of the bolts may recess into the counter-sink holes 120. The shaft of the bolts may pass througb springs. As the bolts are tightened to the clutch flywheel, the springs come under tension, recessing the heads of the bolts into the holes 120, and bringing the posts 106 into contact with a clutch pressure plate.
FIG. 3 is a side view illustration of a clutch finger 300. The finger 300 has an arm 306 and a cam 304. A bolt may be inserted through the hole 308 and secured with a nut to add weight to the end of the arm 306. A pivot may be inserted through the hole 302 at the juncture of the arm 306 and the cam 304. Fingers 300 may be inserted into the slots 110 of the cover 100 and the pivot may be recessed into the slots 112. Retaining screws may be threaded into the holes 114, and tightened until their heads are recessed into the countersink holes 116, thus securing the finger pivots in the slots 112.
Forming a hole 102 in the cover 100 lessens the weight and may accommodate possible protrusions of the transmission system. Forming bays 108 also lessens the weight of the cover 100.
As engine RPMs increase, the arms 306 of the fingers 300 are drawn outward by centrifugal force, rotating the cam 304 against a pressure plate mounted behind the cover 100. Rotation of the cams 304 against the pressure plate increases the force of the frictional coupling between the engine drive train and the axels, reducing slipping of the clutch at higher engine RPMs.
Weight and durability of system components are crucial factors in the performance of engine systems. An improved cover would benefit from further reductions in weight, while either improving or without compromising the durability of the cover.